A Cabinet-level EMU, such as the HJ-EMU200, is a localized energy control unit installed inside energy storage cabinets. It handles real-time monitoring, safety protection, and local control of battery modules and power conversion systems.

The HJ-EMU200 supports data acquisition, fault alarm, battery balancing commands, communication with BMS and PCS, and environmental monitoring. It acts as the local brain of the cabinet, enhancing responsiveness and safety.

Station EMS, like the HJ-EMS400, is a centralized energy management controller designed for multi-cabinet or site-level deployment. It coordinates all EMUs, solar generation, loads, and grid interaction, providing intelligent dispatch and optimization.

Cabinet EMUs handle local control and protection, while the Station EMS oversees the full system, optimizing energy flows between cabinets, PV systems, and the grid. Together, they ensure safe and intelligent operation of the entire energy storage site.

Both EMU and EMS support standard industrial communication protocols (Modbus, CAN, Ethernet) for seamless integration with PCS, BMS, SCADA, and cloud platforms. This enables remote monitoring, firmware upgrades, and data analysis.